probley abit of an idiot question but interface help please

[triphazard]

hey i just got a ti and i think its well sweet, it works via ableton fine and when i hook it up usb i see the interface opition to have it as my output for everything on my mac. when i choose it thou no audio comes out, for instance im liserning to something streamed on the net and it wont even start the playing of it, its not that it says its playing and i hear nothing its tht it wouldnt play, i swape it to my other interface and it works fine.

when i audition sounds via the virus control panel the virus sounds work outta the speakers its just when i wanna play a wav file or such it wont even try.